gms | German Medical Science

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2017)

24.10. - 27.10.2017, Berlin

A novel spatiotemporal delivery system of rhBMP-2 for the regeneration of critical sized bone defects in an ovine large animal model

Meeting Abstract

  • presenting/speaker Jan Henkel - Institute of Health and Biomedical Innovations, Queensland University of Technology, Kelvin Grove, Australia
  • Maria Ann Woodruff - Institute of Health and Biomedical Innovations, Queensland University of Technology, Kelvin Grove, Australia
  • Michael Schütz - Charité Universitätsmedizin Berlin, Centrum für Muskuloskeletale Chirurgie, Berlin, Germany
  • Dietmar Werner Hutmacher - Institute of Health and Biomedical Innovations, Queensland University of Technology, Kelvin Grove, Australia
  • Arne Berner - Charité Universitätsmedizin Berlin, Centrum für Muskuloskeletale Chirurgie, Berlin, Germany

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2017). Berlin, 24.-27.10.2017. Düsseldorf: German Medical Science GMS Publishing House; 2017. DocGR13-1275

doi: 10.3205/17dkou488, urn:nbn:de:0183-17dkou4887

Veröffentlicht: 23. Oktober 2017

© 2017 Henkel et al.
Dieser Artikel ist ein Open-Access-Artikel und steht unter den Lizenzbedingungen der Creative Commons Attribution 4.0 License (Namensnennung). Lizenz-Angaben siehe http://creativecommons.org/licenses/by/4.0/.


Gliederung

Text

Objectives: The treatment of large segmental bone defects resulting from trauma or tumour surgery remains a major challenge in today's clinical practice. We have recently shown that a novel spatiotemporal delivery system composed of a nanofibrous mesh tube and a functionalised alginate hydrogel with BMP significantly increases bone regeneration and improves biomechanical function in a small animal model. In this study, this new technique is trialed in our fully characterised ovine large animal model by combining a melt-electrospun tubular mPCL-CaP microfiber mesh with medical grade sodium alginate hydrogels coupled with RGD and loaded with rhBMP-2.

Methods: A 3cm segmental tibial bone defect was created in 15 adult merino sheep (aged 6-7 years). A melt-electrospun tubular microfiber mesh [medical grade poly-caprolactone coated with calcium phosphate (mPCL-CaP) was slid over both ends of the osteotomy and fixed in situ to bridge the defect site. In group 1 (n=5) the tibial defect site was bridged using the mPCL-CaP tubular microfiber mesh only. In group 2 (n=5), we injected 6ml medical grade sodium alginate hydrogel into the tubular microfiber mesh. In group 3 (n=5) the 6ml of alginate hydrogels injected into the tubular microfiber meshes additionally contained encapsulated rhBMP-2 at a concentration of 1mg per 6 ml. Bone healing was assessed after 6 month post surgery by radiology, micro computed tomography, biomechanical testing and Scanning electron microscopy.

Results: X-rays at 2 months post surgery showed an accentuated callus formation in the defect site for all sheep in group 3. After 6 month post-operative all sheep in group 3 had bridged the defect site entirely with newly formed radio-opaque mineralised callus tissue. Results from biomechanical testing, microCT and histology confirmed this observation with significantly better results for group 3.

Conclusion: The combination of a nanofibrous mesh tube and a functionalised alginate hydrogel with BMP significantly increases bone regeneration in sheep. These results parallel the results of our small animal model and prove that this technique can successfully be translated into large animals. We now investigate this promising spatiotemporal delivery system under conditions that closely resemble human bone regeneration processes and thereby create preclinical evidence for future translation into clinical practice.